The claimed invention relates generally to the field of disc drive data storage devices, and more particularly but not by way of limitation, to a disc drive having a controllably positionable head adjacent a rotatable disc and an airflow control device which extends along the path of travel of the head to reduce and direct air flow generated by rotation of the disc.
Modern disc drives are commonly used in a multitude of computer environments to store large amounts of data in a form that is readily available to an end user. A typical disc drive has one or more rigid magnetic recording discs that are rotated by a spindle motor at a constant high speed.
Each disc has a data storage surface divided into a series of generally concentric data tracks radially spaced across a band having an inner diameter and an outer diameter. Data are stored within the data tracks on the disc surfaces in the form of magnetic flux transitions. The flux transitions are induced by an array of read/write heads. Each data track is divided into a number of data sectors where data are stored in fixed size data blocks.
The read/write heads are supported by flexible suspension assemblies which in turn are supported by rigid actuator arms that project into the disc stack. Each head includes an air bearing surface that, in response to air currents caused by rotation of the disc, causes the head to fly adjacent to the disc surface.
A continuing trend in the industry is the simultaneous reduction in size and increase in data storage capacity and processing speed of modern disc drives. Such improvements have been brought about through a variety of changes in the configurations of the drives, including the use of higher disc rotational speeds. While advantageously reducing latency times (i.e., time spent waiting for a selected data block to reach the head as a particular disc rotates), higher rotational speeds tend to induce a greater degree of turbulence in the airflow established by the rotating discs.
Airflow turbulence is characterized by random fluctuations in the speed and direction of the airflow. Such airflow turbulence can cause unwanted vibration of the discs and heads, leading to undesired head position (run-out) error during operation. Accordingly, a need exists within the art to reduce airflow turbulence near a disc drive head to reduce run-out errors in the drive.
In accordance with preferred embodiments, a disc drive includes a rotatable disc having a disc recording surface configured for rotation in a selected rotational direction. A rotatable actuator is provided adjacent the disc and comprises an arm and a head supported by the arm.
The head is configured to be aerodynamically supported in close proximity to the disc recording surface by air currents generated by rotation of the disc. The rotational direction of the disc is selected so that a given point on the disc that initially starts at a location 180 degrees away from the head will pass the head prior to passing the arm over a complete rotation of the disc.
A stationary airflow control device is disposed upstream of and in close proximity to the head. The airflow control device comprises a diverter member and a screen member which cooperatively form a radially extending channel. The head moves within the channel along an arcuate path of travel across the disc recording surface.
Air currents established by rotation of the disc impinge upon the diverter member. Most of this volume of airflow is diverted away from the head and either passes along the diverter member to the innermost or outermost radii of the disc, or up and over the screen member. However, a small portion of the air currents passes through a gap between the diverter member and the disc recording surface. These air currents have a substantially laminar flow and are used to aerodynamically support the head.
In a preferred embodiment, the disc drive comprises a housing which encloses the disc and the actuator, and the airflow control device is incorporated as part of the housing. This configuration is particularly suited for disc drives having a single disc and for the topmost and bottommost discs in a disc drive having multiple discs. In another preferred embodiment, the airflow control device is disposed between a pair of adjacent discs and has a generally t-shaped cross section to form a pair of channels each shielding a separate head between the discs.
A back-screen preferably projects from a distal edge of the screen member to restrict back-flow of the air currents passing over the exterior surface of the screen member into the channel. A ramp load member is advantageously affixed to the diverter member to secure the head when the disc is in a nonrotational state.
These and various other features and advantages which characterize the claimed invention will be apparent upon reading the following detailed description and upon review of the associated drawings.